caa a22 4500 530098733 20181217030326.0 cr unu---uuuuu 181026e20160106xx s 000 0 eng 10.3929/ethz-b-000110573 doi 10.1038/srep18818 doi (ETHRESEARCH)oai:www.research-collection.ethz.ch:20.500.11850/110573 Size-dependent redox behavior of iron observed by in-situ single nanoparticle spectro-microscopy on well-defined model systems [Elektronische Daten] [Waiz Karim, Armin Kleibert, Urs Hartfelder, Ana Balan, Jens Gobrecht, Jeroen A. van Bokhoven, Yasin Ekinci] Sci Rep Open access ethresearch Understanding the chemistry of nanoparticles is crucial in many applications. Their synthesis in a controlled manner and their characterization at the single particle level is essential to gain deeper insight into chemical mechanisms. In this work, single nanoparticle spectro-microscopy with top-down nanofabrication is demonstrated to study individual iron nanoparticles of nine different lateral dimensions from 80 nm down to 6 nm. The particles are probed simultaneously, under same conditions, during in-situ redox reaction using X-ray photoemission electron microscopy elucidating the size effect during the early stage of oxidation, yielding time-dependent evolution of iron oxides and the mechanism for the inter-conversion of oxides in nanoparticles. Fabrication of well-defined system followed by visualization and investigation of singled-out particles eliminates the ambiguities emerging from dispersed nanoparticles and reveals a significant increase in the initial rate of oxidation with decreasing size, but the reactivity per active site basis and the intrinsic chemical properties in the particles remain the same in the scale of interest. This advance of nanopatterning together with spatially-resolved single nanoparticle X-ray absorption spectroscopy will guide future discourse in understanding the impact of confinement of metal nanoparticles and pave way to solve fundamental questions in material science, chemical physics, magnetism, nanomedicine and nanocatalysis. Creative Commons Attribution 4.0 International http://creativecommons.org/licenses/by/4.0 ethresearch Characterization and analytical techniques ethresearch Chemical physics ethresearch Nanoparticles ethresearch Karim Waiz joint author Kleibert Armin joint author Hartfelder Urs joint author Balan Ana joint author Gobrecht Jens joint author van Bokhoven Jeroen A. joint author Ekinci Yasin joint author Scientific Reports London : Nature Publishing Group 6, p. 18818 2045-2322 http://hdl.handle.net/20.500.11850/110573 text/html WWW-Backlink auf das Repository (Open access) 1 Journal Article ethresearch ETHRESEARCH 856 40 http://hdl.handle.net/20.500.11850/110573 text/html WWW-Backlink auf das Repository (Open access) ETHRESEARCH 700 1- Karim Waiz joint author ETHRESEARCH 700 1- Kleibert Armin joint author ETHRESEARCH 700 1- Hartfelder Urs joint author ETHRESEARCH 700 1- Balan Ana joint author ETHRESEARCH 700 1- Gobrecht Jens joint author ETHRESEARCH 700 1- van Bokhoven Jeroen A. joint author ETHRESEARCH 700 1- Ekinci Yasin joint author ETHRESEARCH 773 0- Scientific Reports London : Nature Publishing Group 6, p. 18818 2045-2322 BK010053 XK010053 XK010000 ETHRESEARCH ETHRESEARCH ETHRESEARCH Journal Article Open access